Route search device and route search method

ABSTRACT

A technology for searching for a recommended route matched to a search condition is provided for route search that involves substitution with a learned route. A route search device comprises: a storage means to store therein, as learned routes, routes corresponding to sections where traveling deviated from recommended routes have been performed; a setting means to set a search condition matched a recommended route; a recommended-route search means to find a recommended route on the basis of the search condition; an application means to select any one of the learned routes that is applicable to the thus found recommended route, and apply the selected learned route to the recommended route; and a display means to display the recommended route to which the learned route has been applied. The storage means stores therein category information of the learned routes in association with the respective learned routes. The application means selects, from the storage means, any one of the learned routes that is associated with the category information matched to the search condition.

TECHNICAL FIELD

The present invention relates to a route search device and a routesearch method.

BACKGROUND ART

There is a navigation system which registers as a learned route, a routeof a section through which traveling is performed with deviation from arecommended route (for example, see Patent Document 1). In this kind ofnavigation system, the recommended route obtained by a route search ispartially replaced by the learned route.

Prior Art Document

-   Patent Document-   [Patent Document 1] Japanese Unexamined Patent Application    Publication No. 2001-174280

DISCLOSURE OF THE INVENTION Problem to Be Solved by the Invention

By the way, in the navigation system described above, there is nodistinction among route types (toll road, ordinary road, narrow road,and the like) of the learned route. Therefore, even in the case where aroute search limiting a target to an ordinary road is requested, thereis a possibility the learned route employs a route including a tollroad. This may result in that a retrieved recommended route does notmeet a search condition designated by a user.

An object of the present invention is to provide a technique forretrieving a recommended route that meets a search condition, in theroute search which performs replacement by a learned route.

Means to Solve the Problem

The present invention for solving the problem as described above isdirected to a route search device such as a navigation system, includinga storage unit adapted to store as a learned route, a route of a sectionthrough which travelling is performed with deviation from a recommendedroute, a setting unit adapted to set a search condition of therecommended route, a recommended route searching unit adapted to searchfor the recommended route based on the search condition, an applicationunit adapted to select from the storage unit, a learned route applicableto the recommended route being retrieved and applying the learned routeto the recommended route, and a display unit adapted to display therecommended route to which the learned route is applied, wherein, thestorage unit stores type information of the learned route, together withthe learned route, and the application unit selects from the storageunit, a learned route having the type information that meets the searchcondition.

The storage unit stores the learned route, the type information, and anorder of priority of the learned route, establishing associations withone another, and the application unit selects from the storage unit, alearned route based on the order of priority, out of the learned routeshaving the type information that meets the search condition.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic block diagram of a navigation system to which oneembodiment of the present invention is applied;

FIG. 2 illustrates a schematic data structure of map data;

FIG. 3 illustrates a schematic data structure of learned routeinformation;

FIG. 4 is a functional block diagram of an arithmetic processing unit;

FIG. 5 is a flow chart showing a learned route registration process;

FIG. 6 is a flow chart showing a route searching process;

FIG. 7(A) illustrates a display example of a recommended route accordingto the present invention, and FIG. 7(B) illustrates a display example ofthe recommended route in the case where there is no applicable learnedroute that meets the search condition;

FIG. 8 is a flow chart showing a learned route application process;

FIG. 9 illustrates an example of associations between the searchcondition and the type information of the learned route; and

FIG. 10(A) illustrates a display example of the recommended routes beingretrieved by multiple route searching according to the presentinvention, and FIG. 10(B) illustrates a display example of therecommended routes being retrieved by the multiple route searching, inthe case where there is no applicable learned route that meets thesearch condition.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, one embodiment of the present invention will be explainedwith reference to the accompanying drawings.

FIG. 1 is a schematic block diagram of the navigation system 100 towhich one embodiment of the present invention is applied. Asillustrated, the navigation system 100 is provided with the arithmeticprocessing unit 1, a display 2, a storage unit 3, an audio input andoutput unit 4 (a microphone 41 and a speaker 42), an input unit 5 (atouch panel 51 and a dial switch 52), a vehicle speed sensor 6, a gyrosensor 7, a GPS receiver 8, an FM multiplex broadcasting receiver 9, andbeacon receiver 10. The navigation system 100 may be a car navigationsystem mounted on a vehicle, or a portable terminal such as a mobilephone and a PDA.

The arithmetic processing unit 1 is a main unit for performing variousprocessing. By wav of example, the arithmetic processing unit 1 includesa CPU (Central Processing Unit) 21 for executing various processing suchas numerical processing and a control of each device, RAM (Random AccessMemory) 22 for storing map data and operation data being read from thestorage unit 3, ROM (Read Only Memory) 23 for storing programs and data,an I/F (interface) 24 for establishing connection between the arithmeticprocessing unit 1 and various hardware. Then, the arithmetic processingunit 1 has a configuration that one device is connected to anothermutually via a bus 25. Functional parts (101 to 107) described below areimplemented by executing programs which the CPU 21 reads into a memorysuch as the RAM 22.

Byway of example, the arithmetic processing unit 1 detects a currentposition based on information outputted from various sensors (6, 7) andfrom the GPS receiver 8. On the basis of the current position beingobtained, the arithmetic processing unit 1 reads out from the storageunit 3, map data necessary to create a display. Furthermore, thearithmetic processing unit 1 graphically expands the map data being readout, and displays the data on the display 2 in such a manner assuperimposing thereon a current position mark (or a moving object markrepresenting a position of the moving object). The arithmetic processingunit 1 uses the map data stored in the storage unit 3 to retrieve anoptimum route (hereinafter, referred to as a “recommended route”)connecting a departure place (current position) with a destinationdesignated by the user. It further uses the speaker 42 of the audioinput and output unit 4 and the display 2 to guide the user.

The display 2 is a unit for displaying the graphics informationgenerated by the arithmetic processing unit 1. The display 2 is made upof a liquid crystal display or an organic EL (Electro-Luminescence)display.

The storage unit 3 is made up of a storage medium such as a CD-ROM, aDVD-ROM, a HDD, and an IC card. This storage medium stores map data 310,learned route information 400, audio data, video data, and the like, forinstance.

FIG. 2 illustrates a schematic data structure of map data 310. Asillustrated, the map data 310 includes link data 320 with respect toeach identification code (mesh ID) 311 indicating a mesh being a regionpartitioned on the map, the link data representing each linkconstituting a road included in the mesh region.

The link data 320 includes with respect to each link identification code(link ID) 321, coordinate information 322 of two nodes (a start node andan end node) constituting the link, a road type 323 indicating typeinformation of the road including the link, link length information 324indicating a length of the link, a link travel time 325, identificationcodes of links respectively connecting to the two nodes (connection linkID) 326, and the like. It is to be noted here that there is adistinction between the start node and the end node being the two nodesconstituting a link, thereby allowing up-line and down-line of the roadto be managed as links different from each other. It is to be noted thatthe road type 323 includes information such as “toll road”, “ordinaryroad”, and “narrow road”. Furthermore, additional information such as atoll fee and a width of road is included in the road type 323.

FIG. 3 illustrates a schematic data structure of the learned routeinformation 400. A route of a section through which traveling isperformed with deviation from a recommended route (hereinafter, referredto as “learned route”) is registered in the learned route information400. By way of example, as illustrated, the learned route information400 is made up of a record 415 with respect to each identification codeof the learned route (learned route ID) 411. Each record 415 stores linkidentification code (link ID) 412 constituting the learned route, thenumber of traveling times through the learned route 413, and typeinformation 414 of the learned route, in such a manner as establishingassociations with one another. Here, as for the link ID 412 indicatingeach link constituting the learned route, the link IDs indicating linksfrom the link of a point deviating from the recommended route (deviationpoint) to the link of a point returning to the recommended route (returnpoint) are registered in the order of traveling sequence. As for thenumber of traveling times 413, the number of traveling times isregistered, serving as a value to represent the priority of the learnedroute. For example, “X times” and “Y times” are registered. As for thetype information 414, a character string is registered, such as “tollroad”, “ordinary road”, and “narrow road”, for instance, indicating typeinformation of the learned route.

Here, referring to FIG. 1 again, the audio input and output unit 4 isprovided with the microphone 41 as an audio input unit, and the speaker42 as an audio output unit. The microphone 41 captures audio data fromthe outside of the navigation system 100, such as voice of a driver andother passengers. The speaker 42 outputs an audio signal generated bythe arithmetic processing unit 1. The microphone 41 and the speaker 42are separately mounted on predetermined portions of a vehicle.

The input unit 5 is a unit for accepting a directive from the user. Theinput unit 5 is made up of the touch panel 51, the dial switch 52, andother hard switches (not illustrated) such as a scroll key and a scalingkey.

The touch panel 51 is an operation panel being a transparent type, to beattached on a display surface of the display 2. The touch panel 51 isused to specify a touch position in association with XY coordinates ofthe image displayed on the display 2, convert the touch position tocoordinates, and output the coordinates, The touch panel 51 is made upof pressure-sensitive type or electrostatic type input detectingelements, or the like,

The dial switch 52 is constructed in rotatable manner, both in theclockwise direction and in the anticlockwise direction, issues a pulsesignal according to a rotation by a predetermined angle, and outputs thepulse signal to the arithmetic processing unit 1. The arithmeticprocessing unit 1 obtains a rotation angle of the dial switch 52 basedon the number of the pulse signals.

The vehicle speed sensor 5, the gyro sensor 7, and the GPS receiver 8are used to detect a current position (location of one's own vehicle)and the like, of a moving object (the navigation system 100). Thevehicle speed sensor 6 is a sensor for outputting vehicle speed datathat is used to calculate a vehicle speed. The gyro sensor 7 is made upof an optical fiber gyroscope, a vibrating gyroscope, or the like, todetect an angular rate according to a rotation of the moving object. TheGPS receiver 8 receives a signal from a GPS satellite, measures adistance between the moving object and the GPS satellite, and a rate ofchange of the distance, with respect to at least three satellites,thereby obtaining the current position and a travelling speed of themoving object.

The FM multiplex broadcasting receiver 9 receives an FM multiplexbroadcasting signal that is transmitted from an FM multiplexbroadcasting station. The FM multiplex broadcasting information includesbrief current traffic information, information on restrictions, SA/PA(service area/parking area) information, parking lot information,weather information, and the like, according to the VICS (VehicleInformation Communication System: registered trademark), and characterinformation and the like, provided by a radio station as FM multiplexgeneral information.

The beacon receiver 10 receives traffic congestion information,information on restrictions, SA/PA information, parking lot information,and the like, transmitted from beacons.

FIG. 4 is a functional block diagram of the arithmetic processing unit1. As illustrated, the arithmetic processing unit 1 includes a maincontroller 101, an input accepting part 102, a display processor 103, aroute searching part 104, a route guiding part 105, a learned routeregistration part 106, and a learned route application part 107.

The main controller 101 performs processing for overall control of eachof the parts in the arithmetic processing unit 1.

The input accepting part 102 accepts a request from the user inputted inthe input unit 5, and analyzes descriptions of the request. The inputaccepting part 102 notifies the main controller 101 of data based on aresult of the analysis. For example, the input accepting part 102accepts a request for power-on or power-off of the navigation system100, or the like, and notifies the main controller 101 of the request.The input accepting part 102 further accepts input data regardingsettings of various functions (e.g., setting of a search condition), thefunctions being held by the navigation system 100, and notifies the maincontroller 101 of the input data.

The display processor 103 displays on the display 2, a map, arecommended route being retrieved, a learned route, various messagesgiven to the user, and the like. Specifically, the display processor 103generates a drawing command to make a display on the display 2 and givesa notice thereof. It is to be noted that, upon displaying the map on thedisplay 2, the display processor 103 extracts from the storage unit 3,the map data of the area requested to be displayed (for example, an areanecessary for displaying the entire recommended route), and generates amap drawing command in a designated drawing format, so as to depictroads, other map structural objects, the current position, thedestination, the recommended route, the learned route, and the like. Thedisplay processor 103 further displays a vehicle mark indicating theposition of the vehicle, and various setting screens, on the map beingdisplayed on the display 2,

The route searching part 104 performs a process for searching for arecommended route (route searching process). Specifically, the routesearching part 104 makes settings such as the departure place,destination, and search condition. Then, the route searching part 104retrieves a route which minimizes cost of the route (e.g., totaldistance and total travel time) connecting designated two points (thedeparture place and the destination), by using Dijkstra's Algorithm orthe like, based on the search condition being set. On this occasion, theroute searching part 104 stores in the memory such as the RAM 22, theidentification code (link ID) 321 of each link that constitutes therecommended route being retrieved, establishing associations between thelink IDs and the links respectively.

The route guiding part 105 performs route guidance along with therecommended route retrieved by the route searching part 104. In somecases, the learned route application part 107 may apply a learned routeto the recommended route that is retrieved by the route searching part104 (replace a partial section of the recommended route with the learnedroute). Details of this processing will be described later. On thisoccasion, the route guiding part 105 performs route guidance by usingthe recommended route after the learned route is applied.

Specifically, the route guiding part 105 displays (highlights), via thedisplay processor 103, the recommended route included in the range ofthe map displayed on the display 2. At this timing, the route guidingpart 105 displays on the recommended route, a moving object mark (carmark) that represents the current position of the moving object(vehicle). Furthermore, the route guiding part 105 compares theinformation of the recommended route with the current position, anddisplays on the display 2, whether or not the vehicle is supposed to gostraight or turn to the left or to the right, prior to passing through amajor crossing point or the like, together with an audio notice to theuser by using the speaker 42 of the audio input and output unit 4.

The learned route registration part 106 performs processing forregistering information regarding the learned route (learned routeregistration process).

Specifically, the learned route registration part 106 stores the link ID321 constituting the route deviating from the recommended route (learnedroute) in the learned route information 400. By way of example, thelearned route registration part 106 stores the link IDs 321, from thelink on the point deviating from the recommended route to the link onthe point returning to the recommended route, according to the order oftraveling sequence.

The learned route registration part 106 stores in the learned routeinformation 400, a result of actual traveling along the learned route.By way of example, if the traveled route with deviation from therecommended route is already stored in the learned route information400, the learned route registration part 106 increments the number oftraveling times 413 which is associated with the route (learned route).It is to be noted here that if the traveled route is already stored inthe learned route information 400, though not deviating from therecommended route, the learned route registration part 106 may incrementthe number of traveling times 413 which is associated with the route(learned route). Furthermore, even though the recommended route is notset, the incrementing process as described above may be performed.

The learned route registration part 106 further stores the typeinformation 414 of the learned route. Here, the type information 414includes “toll road”, “ordinary road”, and “narrow road”, and the like.

The learned route application part 107 performs a process for applyingthe learned route (learned route application process) to the recommendedroute retrieved by the route searching part 104. Specifically, thelearned route application part 107 extracts from the learned routeinformation 400, a learned route applicable to the recommended routebeing retrieved by the route searching part 104. Here, the learned routebeing extracted has the type information 414 which meets the searchcondition of the recommended route. Then, the learned route applicationpart 107 replace a partial section of the recommended route with theextracted learned route. Details of the learned route applicationprocess will be described later.

It is to be noted that the constitutional elements described above arecategorized according to the processing descriptions, so as tofacilitate understanding of the configuration of the navigation system100. Categorizing method of the constitutional elements or the namesthereof may not restrict the scope of the present invention. Theconfiguration of the navigation system 100 may be categorized into morevarious constitutional elements according to processing descriptions. Itis alternatively possible to categorize the elements in such a mannerthat one constitutional element executes more various processing.

It is further possible that each of the functional parts is establishedby using hardware (ASIC, or the like). A piece of hardware may executethe processing of each of the functional parts, or multiple pieces ofhardware may execute the same.

Next, an explanation will be made as to a characteristic behavior of thenavigation system 100 having the configuration as described above.

<Learned Route Registration Process>

FIG. 5 is a flowchart showing the learned route registration processperformed by the navigation system 100.

The learned route registration part 106 of the arithmetic processingunit 1 starts the learned route registration process at the timing whenthe route guiding part 105 starts the route guidance.

Upon starting the learned route registration process, the route guidingpart 105 calculates the current position of the moving object (vehicle)(step S101). By way of example, the route guiding part 105 calculatesthe current position of the moving object by using the vehicle speeddata outputted by the vehicle speed sensor 6, angular velocity datadetected by the gyro sensor 7, and the like. In addition, the routeguiding part 105 modifies the current position by using the output datafrom the GPS receiver 8,

Then, the route guiding part 105 determines whether or not the movingobject has reached the destination (step S102). By way of example, theroute guiding part 105 compares the current position calculated in thestep S101, with the position set as the destination of the recommendedroute. When the current position coincides (approximately coincides)with the destination, it is determined that the moving object hasreached the destination. On the other hand, if the current position doesnot coincide with the destination, it is determined that the movingobject has not reached the destination yet.

Upon determining that the moving object has reached the destination(step S102; Yes), the route guiding part 105 terminates the routeguidance. Accordingly, the learned route registration part 106terminates the present flow (learned route registration process).

On the other hand, upon determining that the moving object has notreached the destination yet, the route guiding part 105 shifts theprocessing to the step S103.

When the processing shifts to the step S103, the route guiding part 105determines whether or not the moving object deviates from therecommended route (step S103). By way of example, the route guiding part105 compares the current position calculated in the step S101, with therecommended route. Then, if the current position does not exist on therecommended route, it is determined that the moving object has deviatedfrom the recommended route. On the other hand, if the current positionexists on the recommended route, it is determined that the moving objecthas not deviated from the recommended route.

When it is determined that the moving object has deviated from therecommended route (step S103; Yes), the route guiding part 105 specifiesfrom the map data 310, a link where the moving object is traveling,based on the current position calculated in the step S101. Then, theroute guiding part 105 temporarily stores the link ID 321 of the linkbeing specified, as a candidate of the learned route, in the memory suchas the RAM 22, Thereafter, the route guiding part 105 returns theprocessing to the step S101. Therefore, the processes from the step S101to the step S103 are repeatedly executed while the moving object istraveling with a deviation from the recommended route, therebyaccumulating the link IDs 321 serving as the learned route candidate.

On the other hand, upon determining that the moving object has notdeviated from the recommended route (step S103; No), the route guidingpart 105 shifts the processing to the step S104.

When the processing is shifted to the step S104, the route guiding part105 determines whether or not the moving object has returned to therecommended route (step S104). In other words, it is determined whetheror not the moving object has returned from the route that is not therecommended route.

Specifically, the route guiding part 105 compares the current positioncalculated in the step S101 just before, with the current positioncalculated in the step S101 two times ago. Then, it is determined thatthe moving object has returned to the recommended route in the casewhere the current position calculated in the step S101 two times agodoes not exist on the recommended route, and the current positioncalculated in the step S101 just before exists on the recommended route.On the other hand, if both the current position calculated in the stepS101 two times ago and the current position calculated in the step S101just before exist on the recommended route, it is determined that anaction taken by the moving object is not a return to the recommendedroute. It is to be noted that if the current position calculated in thestep S101 two times ago does not exist, it is also determined that theaction taken by the moving object is not a return to the recommendedroute.

If it is determined that the moving object has returned to therecommended route (step S104; Yes), the route guiding part 105 shiftsthe processing to the step S105.

On the other hand, if it is determined that the action taken by themoving object is not a return to the recommended route (it keeps ontraveling along the recommended route), the route guiding part 105returns the processing to the step S101. Therefore, while the movingobject keeps on traveling on the recommended route, the route guidingpart 105 repeatedly executes the processes from the step S101 to thestep 3104.

When the processing is shifted to the step S105, the learned routeregistration part 106 registers as a learned route, the route the movingobject has travelled with deviation from the recommended route (stepS105).

Specifically, the learned route registration part 106 firstly reads thelink ID 321 serving as a candidate of the learned route that is storedin the memory in the step S103. Then, it is checked whether or not thelearned route candidate being read out is the learned route that isalready registered in the learned route information 400.

Here, in the case where the learned route candidate is alreadyregistered, the learned route registration part 106 increments thenumber of traveling times 413 being associated with the learned route ID411 of the learned route (in other words, modify the value to beincremented by “1”).

On the other hand, if the candidate of the learned route has not beenregistered yet, the learned route registration part 106 adds thecandidate as the learned route, to the learned route information 400.

Byway of example, the learned route registration part 106 adds a record415 to the learned route information 400, and stores the learned routeID 411, the link ID 412 of the link constituting the learned route, thenumber of traveling times 413, and the type information 414, in such amanner as establishing associations with one another.

Here, as for the link ID 412 of the link constituting the learned route,the link IDs 321 accumulated in the memory in the step S103 are storedin the order of traveling sequence. In addition, data indicating “onetime” is stored as the number of traveling times 413. It is furtherpossible that as for the link ID 412 of a deviation point, the learnedroute registration part 106 may store the link ID in association withthe coordinates of the deviation point. Similarly, as for the link ID412 of the returning point, it is also possible that the link ID isstored in association with the coordinates of the returning point.

The type information 414 stores data indicating the “toll road”,“ordinary road”, “narrow road, and the like. Here, the type information414 is determined by using the road type 323 which is associated withthe link ID 321. Specifically, in the case where at least one toll roadis included in the links constituting the learned route, the learnedroute registration part 106 stores the learned route as the “toll road”.If the links constituting the learned route include neither the tollroad nor the narrow road, the learned route is stored as the “ordinaryroad”. In addition, in the other case (that is, the links constitutingthe learned route do not include the toll road but include at least onenarrow road), the learned route is stored as the “narrow road”.

Registration of the learned route in the step S105 is performed everytime when the moving object returns to the recommended route. Therefore,even though the traveling deviates from the recommended route more thanonce, between the departure place and the destination, it is possible toregister each learned route in the learned route information 400.

After the learned route is registered, the learned route registrationpart 106 returns the process to the step S101.

<Route Searching Process>

FIG. 6 is a flowchart showing the route searching process executed bythe navigation system 100.

The route searching part 104 of the arithmetic processing unit 1 startsthe route searching process based on a directive from a user, forinstance.

Upon starting the route searching process, the route searching part 104sets a departure place and a destination (step S201), For example, theroute searching part 104 displays a predetermined setting screen andaccepts from the user, a designation of the departure place and thedestination.

Next, the route searching part 104 sets a search condition of arecommended route (step S202), By way of example, the route searchingpart 104 displays a predetermined setting screen, and accepts an inputof the search condition from the user.

Here, a settable search condition includes, for instance, “the firsttoll road priority” for making a search putting a priority on a tollroad, “the second toll road priority” for making a search for a routedifferent from the recommended route being retrieved based on the searchcondition of “the first toll road priority”, “the third toll roadpriority” for making a search putting a priority on the toll road inconsideration of a toll fee, “the first ordinary road priority” formaking a search putting a priority on an ordinary road, “the secondordinary road priority” for making a search putting a priority on a wideroad and searching for a road different from the recommended road beingretrieved based on “the first ordinary road priority”, “distancepriority” for making a search so that a distance from the departureplace to the destination becomes the shortest, and the like.

Next, the route searching part 104 acquires traffic congestioninformation (step S203). Specifically, with the use of the FM multiplebroadcasting receiver 9, the beacon receiver 10, and the like, the routesearching part 104 acquires traffic congestion information (includingrestriction information, and the like) in an area being the routesearching target (e.g., the area including a route from the departureplace to the destination).

Subsequently, the route searching part 104 performs the route searchingprocess (step S204). Specifically, the route searching part 104 searchesfor a recommended route from the departure place to the destination setin the step S201, based on the search condition set in the step S202.

By way of example, in the case where “the first toll road priority” isset as the search condition, the route searching part 104 searches for arecommended route, by using the link (link ID 321) having the road type323, i.e., “toll road”, “ordinary road”, or “narrow road”.

In the case where “the second toll road priority” is set as the searchcondition, the route searching part 104 searches for a recommendedroute, by using the link having the road type 323, i.e., “toll road”,“ordinary road”, or “narrow road”. It is to be noted that even though alink has the road type 323 of “toll road”, the link that is used in therecommended road being retrieved based on “the first toll road priority”is excluded. In other words, the toll road used in the recommended routebeing retrieved based on the search condition of “the second toll roadpriority” is at least different from the toll road used in therecommended route being retrieved based on the search condition of “thefirst toll road priority”.

In the case where “the third toll road priority” is set as the searchcondition, the route searching part 104 searches for a recommendedroute, by using the link having the road type 323, i.e., “toll road”,“ordinary road”, or “narrow road”. It is to be noted that a link havingthe road type 323 of a low toll fee (e.g., the lowest fee) isprioritized, out of the links having the road type 323 of “toll road”.

In the case where “the first ordinary road priority” is set as thesearch condition, the route searching part 104 uses a link having theroad type 323 of “ordinary road” or “narrow road”, to search for arecommended route.

In the case where “the second ordinary road priority” is set as thesearch condition, the route searching part 104 uses a link having theroad type 323 of “ordinary road” to search for a recommended route. Itis to be noted that even though the link has the road type 323 of“ordinary road”, the link used for the recommended route that isretrieved based on the search condition of “the first ordinary roadpriority” is excluded. Then, among the links that are not excluded, alink having the road type 323 of wide road width (e.g., the widest road)is prioritized.

In the case where “distance priority” is set as the search condition,the route searching part 104 uses a link having the road type 323 of“toll road” or “ordinary road” to search for a recommended route. It isto be noted that a link with a total distance from the departure placeto the destination being the shortest (e.g., the shortest distance) isused, out of the links having the road type 323 of “toll road” or“ordinary road”.

In the case where “the first toll road priority”, “the second toll roadpriority”, “the third toll road priority”, or “the first ordinary roadpriority” is set out of the search conditions described above, the routesearch is performed in consideration of traffic congestion information.Specifically, the route searching part 104 reads the traffic congestioninformation acquired in the step S203, and as for the link beingcongested, it is excluded from the target for a recommended routesearch, or relegated in a lower priority. On the other hand, if “thesecond ordinary road priority” is set, out of the search conditionsdescribed above, the recommended route is retrieved putting the highestpriority on the road width, and the traffic congestion information isnot considered. Similarly, if the “distance priority” is set, therecommended route is retrieved putting the highest priority on thedistance from the departure place to the destination, and the trafficcongestion information is not considered.

After searching for a recommended route based on the search condition asdescribed above, the route searching part 104 stores in the memory suchas the RAM 22, the links ID 321 of the respective links that constitutethe recommended route being retrieved.

Next, the learned route application part 107 performs the learned routeapplication process (step S205). In other words, the learned routeapplication part 107 selects the learned route having the typeinformation 414 that meets the search condition, and performs a processto apply the learned route to the recommended route retrieved in thestep S204 (to replace the recommended route with the learned route).Details of the learned route application process will be describedlater.

Then, the route guiding part 105 displays on the display 2, a resultobtained in the step S205 (a recommended route after the learned routeis applied, and the like) (step S206).

FIG. 7(A) illustrates a display example where a recommended route isdisplayed after the learned route is applied, together with therecommended route retrieved based on the search condition. Asillustrated, if the search condition of the recommended route is “thefirst ordinary road priority”, a learned route having the typeinformation 414 being “ordinary road” (or “narrow road”) is selected anddisplayed. In other words, the learned route is displayed having thetype information 414 that meets the search condition. The route guidingpart 105 highlights the section of the learned route (dotted line), insuch a manner as displaying with a color different from other routes, orthe like.

On the other hand, if any of the learned routes having the typeinformation that meets the search condition is not applicable, it is notpossible to display the recommended route as shown in FIG. 7(A).

FIG. 7(B) illustrates a display example in the case where the learnedroute having the type information that meets the search condition is notapplicable. As illustrated, there is a possibility that the learnedroute including a toll road is displayed, even though the searchcondition of the recommended route is “the first ordinary roadpriority”. With this result, it cannot be said that the recommendedroute necessary for the user is displayed.

Referring to FIG. 6 again, the route searching part 104 terminates thisflow after the process in the step S206.

Next, details of the learned route application process (step S205) willbe explained.

<Learned Route Application Process>

FIG. 8 is a flowchart showing the learned route application processperformed by the navigation system 100.

When the processing shifts to the step S205, the learned routeapplication part 107 of the arithmetic processing unit 1 extracts alearned route serving as an application candidate from the learned routeinformation 400 (step S301). Specifically, the learned route applicationpart 107 extracts from the learned route information 400, the learnedroute having the type information 414 that meets the search conditionset in the step S202. It is to be noted that the learned route havingneither a deviation point nor a returning point on the recommended routeretrieved in the step S204 is not extracted. Therefore, the learnedroute application part 107 extracts from the learned route information400, the learned route having the type information 414 that meets thesearch condition, out of the learned route (record 415) included in thelinks constituting the recommended route where a link having thedeviation point and a link having the returning point are included.

FIG. 9 illustrates an example of associations between the searchcondition and the type information 414 of the learned route.

As illustrated, when “the first toll road priority” is set as the searchcondition, the learned route application part 107 extracts the learnedroute having the type information 414 of “toll road”, “ordinary road”,or “narrow road”.

In the case where “the second toll road priority” is set as the searchcondition, the learned route application part 107 extracts the learnedroute having the type information 414 of “toll road”, “ordinary road”,or “narrow road”. It is to be noted that even though the learned roadhas the type information 414 of “toll road”, the learned road which hasbeen applied to the recommended route retrieved based on the searchcondition of “the first toll road priority”, is excluded. With thisexclusion, it is not possible to extract a learned route identical tothe learned route that has been applied to the recommended route beingretrieved based on the search condition of “the first toll roadpriority”. Even though the learned route has the type information 414 of“ordinary road”, this learned route is not extracted if the section (onthe recommended route) of the target for application (replacementtarget) is “toll road”. In other words, the learned route being theordinary road cannot substitute for the section of toll road.

In the case where “the third toll road priority” is set as the searchcondition, the learned route application part 107 extracts the learnedroute having the type information 414 of “ordinary road” or “narrowroad”. Even though the learned route has the type information 414 of“ordinary road”, this learned route is not extracted, if the section (onthe recommended route) of the target for application (replacementtarget) is a “toll road”. In other words, the learned route being theordinary road cannot substitute for the section of toll road. It is tobe noted that the reason why the learned route having the typeinformation 414 of “toll road” is not extracted here is that therecommended route retrieved in the step S204 is selected puttingpriority on the toll road (link) of low fee. If the recommended route isreplaced by other toll road (learned route), the toll fee may not be lowany more.

If “the first ordinary road priority” is set as the search condition,the learned route application part 107 extracts a learned route havingthe type information 414 of “ordinary road” or “narrow road”.

In the case where “the second ordinary road priority” is set as thesearch condition, the learned route application part 107 extracts alearned route having the type information 414 of “ordinary road”. It isto be noted that even though the learned road has the type information414 of “ordinary road”, the learned road which has been applied to therecommended route retrieved based on the search condition of “the firstordinary road priority”, is excluded. With this exclusion, it is notpossible to extract a learned route identical to the learned route thathas been applied to the recommended route being retrieved based on thesearch condition of “the first ordinary road priority”. It is to benoted that the reason why the learned route having the type information414 of “narrow road” is not extracted here is that the recommended routeretrieved in the step S204 is selected putting priority on a wide road(link). If the recommended route is replaced by a learned road being“narrow road”, the recommended route may not be a wide road any more.

In the case where “distance priority” is set as the search condition,the learned route application part 107 does not extract any of thelearned routes. This is because the recommended route retrieved in thestep S204 is selected putting priority on the road (link) which makesthe distance from the departure place to the destination to be short(e.g., the shortest distance). If the recommended route is replaced bythe learned route, the recommended route may not be assumed as a shortdistance to reach the destination.

As thus described, the learned route application part 107 extracts as alearned route of application candidate, a learned route (record 415)with the type information 414 that meets the search condition. It is amatter of course that if there is more than one learned route having thetype information 414 that meets the search condition, the learned routeapplication part 107 extracts those multiple learned routes. Then, thelearned route application part 107 stores those extracted learned routesin the memory such as the RAM 22.

Referring to FIG. 8 again, the learned route application part 107selects one learned route out of the learned routes extracted in thestep S301, based on the priority (e.g., the number of traveling times)(step S302). By way of example, the learned route application part 107specifies one learned route as a learned route as an applicationcandidate, which is associated with the record 415 having the maximumnumber of traveling times 413.

Then, the learned route application part 107 deletes from the learnedroutes extracted in the step S301, any learned route that is notapplicable (step S303). Specifically, the learned route application part107 deletes the learned route which is not applicable to an identicalrecommended route simultaneously with the learned route specified in thestep S302. In other words, the learned route application part 107deletes the learned routes (b, c, and d) that include at least eitherone of the deviation point and the returning point, between thedeviation point and the returning point of the learned route a, which isspecified in the step S302. In addition, the learned route e is alsodeleted, which includes between its deviation point and returning point,both the deviation point and the returning point of the learned route aspecified in the step S302. Here, the start node 322 of the link on thedeviation point, coordinates of the deviation point, and the like, areused for specifying the deviation point. For specifying the returningpoint, the end node 322 of the link on the returning point, coordinatesof the returning point, and the like, are used.

Subsequently, the learned route application part 107 determines whetheror not any other learned route exists which serves as the applicationcandidate (step S304). Specifically, the learned route application part107 checks whether or not any remaining learned route exists, afterexcluding the learned route that is specified in the step S302 and thelearned route deleted in the step S303, from the learned routesextracted in the step S301. If there is any learned route stillremaining, it is determined that other learned route exists which servesas the application candidate. On the other hand, if there is no learnedroute still remaining, it is determined that no other learned routeexists which serves as the application candidate.

If it is determined that any other learned route exists which serves asthe application candidate (step S304; Yes), the learned routeapplication part 107 returns the process to the step S302. Then, thelearned route application part 107 repeatedly executes the processesfrom the step S302 to the step S304, until the time when there is noother learned route serving as the application candidate. Accordingly,it is possible to apply multiple applicable learned routes, to onerecommended route retrieved in the step S204.

On the other hand, when it is determined that there is no other learnedroute serving as the application candidate (step S304; No), the learnedroute application part 107 shifts the process to the step S305.

The learned route application part 107 applies the learned routespecified in the step S302 to the recommended route retrieved in thestep S204 (step S305). Specifically, the learned route application part107 replaces a part of the recommended route retrieved in the step S204with the learned route specified in the step S302. Then, the learnedroute application part 107 stores the recommended route (the link ID 321constituting the recommended route) after the replacement is performed,in the memory such as the RAM 22.

Thereafter, the learned route application part 107 terminates the flowand shifts the process to the step S206.

It is to be noted that the processing units of the aforementioned floware categorized according to major processing details, to facilitateunderstanding of the processes in the navigation system 100.Categorizing method of the processing steps or the names thereof may notrestrict the scope of the present invention. The processes performed bythe navigation system 100 may be further divided into more processingsteps. Alternatively, one processing step may execute more processes.

The embodiment of the present invention in the foregoing description isintended to be illustrative, rather than limiting, of the spirit andscope of the invention. Therefore, those skilled in the art will readilyappreciate many alternatives, modifications, and variations thereof.

By way of example, in the present embodiment, the route searching part104 searches for one recommended route which serves as a candidate.However, the present invention is not limited to this example. The routesearching part 104 may search for multiple recommended routes (socalled, “multiple route searching”).

When the multiple route searching is performed, the route searching part104 searches for multiple recommended routes in the step S204, therecommended routes satisfying the search condition set in the step S202,

For example, the route searching part 104 searches for a firstrecommended route satisfying the search condition of “the first tollroad priority”, and searches for a second recommended route satisfyingthe search condition of “the second toll road priority”.

FIG. 10(A) illustrates a display example of two recommended routes beingretrieved based on two search conditions, represented by solid lines. Asillustrated, the first recommended route satisfying the search conditionof “the first toll road priority” and the second recommended routesatisfying the search condition of “the second toll road priority” aredisplayed respectively.

Then, the learned route application part 107 subjects each of therecommended routes retrieved in the step S204 to the process in the stepS205 (processes from the step S301 to the step S305). Accordingly, thelearned route application part 107 applies the learned route with thetype information 414 that meets the search condition, with respect toeach. recommended route.

Therefore, the learned route application part 107 is allowed to applythe learned routes different from each other (the first learned routeand the second learned route) to the respective recommended routes asillustrated in FIG. 10(A).

Similar to the case of displaying one learned route, the route guidingpart 105 highlights the multiple learned routes (dotted lines), in sucha manner as displaying with a color different from other routes. Withthis configuration, the user is allowed to easily select whichrecommended route to take, so as to travel up to the destination.

On the other hand, if the learned route having the type information thatmeets the search condition is not applicable, the recommended route asshown in FIG. 10(A) cannot be displayed.

FIG. 10(B) illustrates a display example in the case where any learnedroute with the type information that meets the search condition is notapplicable. As illustrated, there is a possibility that an identicallearned route is applied to each of the recommended routes (the firstrecommended route and the second recommended route). Consequently, thereis only one learned route that can be displayed. It may result in thatthe multiple route searching becomes meaningless.

It is further possible configure in such a manner that even thoughmultiple route searching is not performed, multiple recommended routesare retrieved. On this occasion, when the search condition of “the firsttoll road priority” is set, a second recommended route satisfying “thesecond toll road priority” is retrieved without accepting the settingfrom the user. Similarly, when the search condition of “the firstordinary road priority” is set, a second recommended route satisfying“the second ordinary road priority” is retrieved without accepting thesetting from the user.

EXPLANATION OF REFERENCES

1 . . . ARITHMETIC PROCESSING UNIT, 2 . . . DISPLAY, 3 . . . STORAGEUNIT, 4 . . . AUDIO INPUT AND OUTPUT UNIT, 5 . . . INPUT UNIT, 6 . . .VEHICLE SPEED SENSOR, 7 . . . GYRO SENSOR, 8 . . . GPS RECEIVER, 9 . . .FM MULTIPLEX BROADCASTING RECEIVER, 10 . . . BEACON RECEIVER, 21 . . .CPU, 22 . . . RAM, 23 . . . ROM, 24 . . . INTERFACE (I/F), 41 . . .MICROPHONE, 42 . . . SPEAKER, 51 . . . TOUCH PANEL, 52 . . . DIALSWITCH, 100 . . . NAVIGATION SYSTEM, 101 . . . MAIN CONTROLLER, 102 . .. INPUT ACCEPTING PART, 103 . . . DISPLAY PROCESSOR, 104 . . . ROUTESEARCHING PART, 105 . . . ROUTE GUIDING PART, 106 . . . LEARNED ROUTEREGISTRATION PART, 107 . . . LEARNED ROUTE APPLICATION PART, 310 . . .MAP DATA, 311 . . . MESH ID, 320 . . . LINK DATA, 321 . . . LINK ID, 322. . . START NODE, END NODE, 323 . . . ROAD TYPE, 324 . . . LINK LENGTH,325 . . . LINK TRAVEL TIME, 326 . . . START CONNECTION LINK, ENDCONNECTION LINK, 400 . . . LEARNED ROUTE INFORMATION, 411 . . . LEARNEDROUTE ID, 412 . . . LINK ID, 413 . . . THE NUMBER OF TRAVELING TIMES,414 . . . TYPE INFORMATION, 415 . . . RECORD

1. A route search device, comprising, a storage unit adapted to store asa learned route, a route of a section through which travelling isperformed with deviation from a recommended route, a setting unitadapted to set a search condition of the recommended route, arecommended route searching unit adapted to search for the recommendedroute based on the search condition, an application unit adapted toselect from the storage unit, a learned route applicable to therecommended route being retrieved and applying the learned route to therecommended route, and a display unit adapted to display the recommendedroute to which the learned route is applied, wherein, the storage unitstores type information of the learned route, together with the learnedroute, and the application unit selects from the storage unit, a learnedroute having the type information that meets the search condition. 2.The route search device according to claim 1, wherein, the storage unitstores the learned route, the type information, and a priority order ofthe learned route, being associated with one another, and theapplication unit selects from the storage unit, the learned routeaccording to the priority order, out of the learned route having thetype information that meets the search condition.
 3. The route searchdevice according to either of claim 1 and claim 2, wherein, the settingunit sets as the search condition, either of a first condition forsearching for the recommended route putting a priority on a toll road,and a second condition for searching for the recommended route putting apriority on an ordinary road, the storage unit stores as the typeinformation, information items indicating at least the toll road and theordinary road, and the application unit selects from the storage unit,the learned route having either of the type information of the toll roadand the type information of the ordinary road, upon setting the firstcondition as the search condition, and selects from the storage unit,the learned route having the type information of the ordinary road, uponsetting the second condition as the search condition.
 4. The routesearch device according to claim 3, wherein, the storage unit stores asthe type information, information items indicating at least any of thetoll road, the ordinary road, and a narrow road, the application unitselects from the storage unit, when the first condition is set as thesearch condition, the learned route having the type information of anyof the toll road, the ordinary road, and the narrow road, determines afirst recommended route by applying the leaned route to the recommendedroute being retrieved in the recommended route searching unit, furtherselects from the storage unit, the learned route that has not beenapplied to the first recommended route, out of the learned route havingthe type information of any of the toll road, the ordinary road, and thenarrow road, and determines a second recommended route by applying thelearned route to the recommended route, the application unit selectsfrom the storage unit, when the second condition is set as the searchcondition, the learned route having the type information of either ofthe ordinary road and the narrow road, determines a third recommendedroute by applying the leaned route to the recommended route beingretrieved in the recommended route searching unit, further selects fromthe storage unit, the learned route that has not been applied to thethird recommended route, out of the learned route having the typeinformation of the ordinary road, and determines a fourth recommendedroute by applying the learned route to the recommended route, and thedisplay unit displays, when the first condition is set as the searchcondition, the second recommended route together with the firstrecommended route, and when the second condition is set as the searchcondition, the fourth recommended route together with the thirdrecommended route.
 5. A route search method, comprising, a storing stepfor storing in a storage medium as a learned route, a route of a sectionthrough which travelling is performed with deviation from a recommendedroute, a setting step for setting a search condition of the recommendedroute, a recommended route searching step for searching for therecommended route based on the search condition, an application step forselecting from the storage medium, a learned route applicable to therecommended route being retrieved and applying the learned route to therecommended route, and a displaying step for displaying the recommendedroute to which the learned route is applied, wherein, the storing stepstores type information of the learned route, together with the learnedroute, and the application step selects from the storage medium, alearned route having the type information that meets the searchcondition.